Synthesis, Property Characterization and Photocatalytic Activity of the Novel Composite Polymer Polyaniline/Bi2SnTiO7

A novel polyaniline/Bi2SnTiO7 composite polymer was synthesized by chemical oxidation in-situ polymerization method and sol-gel method for the first time. The structural properties of novel polyaniline/Bi2SnTiO7 have been characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray spectrometry. The lattice parameter of Bi2SnTiO7 was found to be a = 10.52582(8) A. The photocatalytic degradation of methylene blue was realized under visible light irradiation with the novel polyaniline/Bi2SnTiO7 as catalyst. The results showed that novel polyaniline/Bi2SnTiO7 possessed higher catalytic activity compared with Bi2InTaO7 or pure TiO2 or N-doped TiO2 for photocatalytic degradation of methylene blue under visible light irradiation. The photocatalytic degradation of methylene blue with the novel polyaniline/Bi2SnTiO7 or N-doped TiO2 as catalyst followed first-order reaction kinetics, and the first-order rate constant was 0.01504 or 0.00333 min−1. After visible light irradiation for 220 minutes with novel polyaniline/Bi2SnTiO7 as catalyst, complete removal and mineralization of methylene blue was observed. The reduction of the total organic carbon, the formation of inorganic products, SO42− and NO3−, and the evolution of CO2 revealed the continuous mineralization of methylene blue during the photocatalytic process. The possible photocatalytic degradation pathway of methylene blue was obtained under visible light irradiation.